Lecture 11: Avian Anatomy Flashcards
Birds see with which part of their brain?
Midbrain. Objects must be moving in relation to bird in order for them to see it.
Which aortic arch develops in birds?
right aortic arch
The premaxilla is present in birds, but absent in mammals
:)
How do the nasal and oral cavities communicate in the bird?
via the choana
fx of craniofacial hinge
allows birds to literally unhinge their beak. A synovial joint, well developed in psittacines.
major sinus in birds
infraorbital sinus
bird vertebral formula
C14 T7 (L-S)14 Cd6.
What allows for significant head rotation in birds?
single occipital condyle
fx of the notarium
fused in thoracic region to provide stability during wing downbeat
synsacrum
the fused lumbosacral area
pygostyle
the last vertebra; where the tail feathers attach
compare sternal ribs in birds vs. costal cartilage in mammals
sternal ribs have ossified, whereas they are cartilaginous in mammals
pectoral girdle is comprised of:
scapula, clavicle, and coracoid bones
What structures push the wings OUT/act as struts?
clavicle and coracoid bones
the dorsal wall of the thorax is formed by the:
notarium
the lateral wall of the thorax is formed by the:
ribs
fx of uncinate processes of bird ribs
project caudally from each rib to overlap the succeeding rib. Overlap provides stability and allows for expansion during inspiration/expiration
ventral wall of thorax formed by:
sternum
fx of keel
supports the abdominal viscera and provides attachment to the large flight muscles
major m. that elevates the wing*
deep pectoral m.
major m. that compresses the wing during the downbeat*
superficial pectoral m.
fx of clavicles
act as struts or springs that hold wings away from midline
how does humerus of birds differ from mammals?
contains a large air sac extension through a pneumatic foramen
where do secondary flight feathers attach?
ulna
Name the 2 bones of the bird carpus. Why only 2?
ulnar and radial carpals. No concussion absorption necessary in the bird forelimb
where do primary flight feathers attach?
carpometacarpus
carpometacarpus in birds is comprised of which bones?
fused metacarpals II, III, and IV and distal row of carpal bones
which digits are present in birds?
II, III, IV
fx of antitrochanter of ilium
allows birds to stand on 1 leg
What forms the sciatic foramen? What passes through this foramen?
Ischium. sciatic n. and a. pass through it
fx of unfused pubis bones
allows for passage of eggs in females
Major flight muscles
superficial and deep pectoral mm.
longest bone of pelvic limb
tibiotarsus. Results from fusion of the tibia with the prox. row of tarsal bones
tarsometatarsus results from fusion of which bones?
distal row of tarsal bones and metatarsal bones II, III, IV
hock joint is formed by articulation b/w which 2 bones?
tibiotarsus and tarsometatarsus
which digit is directed caudally in birds? How many phalanges does it have?
digit I. Has 3 phalanges
origin, insertion, and function of the superficial pec
O: keel/clavicle/sternal ribs
I: humerus
Fx: wing “downbeat” caused by adduction and depression of the wing
Origin, Insertion, Action of deep pectoral m.
O: sternum
I: humerus (via a tendon which travels through the foramen triosseum)
A: abduction/elevation of wing
“The triceps and extensor carpi radialis muscles and the radial n. are as important to flight in the bird as they are to limb support and locomotion in mammals.”
:)
propatagium
the “wing membrane.” Has small patagial muscles which pull on the membrane to change it’s shape. VERY important for flight
pineoning procedure
resecets part of the extensor carpi radialis m. so the bird can’t fly
Unique to birds: a sciatic artery that runs with the sciatic n.
:)
venipuncture performed in R or L jugular vein?
R
the caudal portion of the larynx is called the:
syrinx
How are vocal sounds produced in birds?
by vibration of the lateral and medial walls of the membranous proximal bronchii
cartilages of the cranial portion of the larynx of birds
dual cricoid and arytenoid
Why is there no separation of the coelomic (body cavity in birds?
No diaphragm to separate coelomic cavity into thoracic and abdominal cavities
fx of air sacs
store air and promote complete filling of the passive lungs
Where are air sacs located?
thoracic and abdominal cavities, pneumatic spaces of several bones. They all connect directly with the secondary bronchii
crop
diverticulum of the esophagus (normally on the R side) which functions as a storage organ for ingested food and as a source of “crop millk”
fx of gizzard
grinds up food material b/c birds don’t have teeth/lips. synonymous with ventriculus
which organ surrounds the pancreas in birds?
duodenum
the colon extends from ___ to ____
from ileum to cloaca
cloaca
common junction of the digestive, urinary, and reproductive tracts
Do birds have a urethra?
no
vent is to birds as ___ is to mammals
anus
coprodeum
cranial portion of the cloaca that receives the colon
urodeum
middle portion of cloaca that receives the ureters and repro tracts
proctodeum
caudal portion of the cloaca that receives the duct of the cloacal bursa (bursa of fabricius)
